Prevalence and causes of iron deficiency anemias in infants aged 9 to 12 months in Estonia

Objective. To investigate the prevalence and causes of iron deficiency anemia in infants aged 9 to 12 months in Estonia.
Material and methods. Every second child aged 9–12 months was randomly selected from primary medical centers in seven counties from all over Estonia. A questionnaire concerning eating habits and lifestyle was sent to their parents. Sixty-five percent (n=195) of contacted families agreed to participate in the study. Mean corpuscular volume and hemoglobin, serum ferritin, and soluble transferrin receptor levels were measured in 171 infants. Anemia was defined when hemoglobin level was lower than 105 g/L, and iron deficiency when ferritin level and mean corpuscular volume were lower than 12 µg/L and 74 fL, respectively.
Results. The prevalence of iron deficiency was 14.0% and iron deficiency anemia 9.4%. Birthweight less than 3000 g was the main risk factor for iron deficiency (OR=9.4; P<0.0005). Infants fed with breast milk and solid food had lower ferritin concentration (18.5 µg/L, 95% CI 14.0–23.0) than infants fed with formula and solid food (32.8 µg/L, 95% CI 26.6–39) (P<0.005).
Conclusion. Iron deficiency anemia is common among 9–12-month-old Estonian infants. The main risk factor for iron deficiency was birthweight less than 3000 g.